A "PSA" ("Pressure Swing Adsorption device") of this type is described in the document EP-A-480.840 in the name of the applicant.
This document describes a device in which the gas distribution to and from the adsorption units is effected radially, the sequential supply and withdrawal means for the gas being confined to the interior of the rotatable assembly, in a voluminous arrangement which is difficult to produce and thus relatively troublesome.